In "The Little Prince" the prince has learned that the heart is important in recognizing the things that really matter in life, he is still sad. The prince is lonely and yearns for his rose. The prince fails to see that it is his love which makes the rose special. This love also binds him to the rose.
Toward the end of the story, the prince and narrator go find a well. After they find the well and are quenched by the waters, they come to realize that people often forget what really matters in life. The prince then plans with the snake for the prince's return to his planet. Even though the pilot fixes the prince's plane, the snake bites the prince. This severity of the act is emphasized by the prince falling to the sand, but in silence.
The next day the narrator does not find the prince. Perhaps, the prince has made his way to his asteroid, thinks the narrator. In the stars, the narrator believes that he can hear the laughter of the prince. The stars, or this hope, is what eases the narrator's mind.
Still, the narrator begins to despair and worries about the prince and even his flower. He wonders if the sheep he drew ate the prince's rose. This makes the narrator sad since he knew the importance of this little flower to his friend the prince. What if the prince were to not find the rose, this would be sad indeed. At the end of the story, the narrator even calls upon the reader to help in the search of the prince.